1. Field of the Invention
This invention relates to an inflatable lining for shoes, boots and the like, and in particular, relates to an inflatable lining with a pump to pressurize the lining and induce air circulation through the shoe.
2. Brief Statement of the Prior Art
Inner soles have been provided for shoes and boots which are formed of a compressible, elastic material such as cellular plastic foams, foam rubber, etc. These inner soles have provided only limited shock absorbency, resulting in little or no significant improvement in wearer comfort.
Some prior investigators have provided inner soles with inflated cushions at either the toe and heel areas, and some have provide cushions at both areas with circulation between the two cushions. The cushions have been provided with mechanisms to circulate air and ventilate the shoe or boot during walking activities. Examples of these are: U.K. Pat Nos. 2,189,679 and 357,391; U.S. Pat. Nos. 3,180,039, 2,716,293, 1,213,941 and German Pat. No. 3,144,207.
In some foot apparel, notably in ski boots, an outer shell is molded from plastic and is lined with an inner shoe. Adjustment has been made to the tightness of the outer shell and air bags have been provided across the instep region of the shoe, and elsewhere, and have been provided with an air pump to pressure the air bags, creating pressure about the foot and snugness of the fit of the ski boot. U.S. Pat. No. 4,730,403 and German Pat. No. 2,321,817 are representative of these ski boots.
A water-filled inner sole for shoes has recently been marketed under the tradename "Walk On Water". While this is an attempt to increase wearer comfort, water is noncompressible and the inner sole cannot be adjusted for firmness, and cannot provide shock absorbency. Addtionally, water is unsuited for use in freezing climates.
None of the aforementioned prior devices provides a simple, inexpensive solution to comfortable wear and walking in a shoe or boot. The foam inner soles have only a limited value and limited shock absorbency. The remainder of the prior devices, including the pressurization system for ski boots are relatively complex and costly and are often too bulky and cumbersome. Consequently, these devices are not readily acceptable for everyday activities.